Methods and systems for reducing the concentration of amine in wash liquid used in industrial processing

Abstract

A method for reducing the concentration of amines in a wash liquid stream exiting a wash section in an acid gas scrubbing process includes introducing the wash liquid stream exiting the wash section of the acid gas scrubbing process to an adsorbent material, wherein the wash liquid stream has a first concentration of amines. The wash liquid stream having the first concentration of amines is flowed through the adsorbent material, and the adsorbent material retains at least a portion of the amines thereby providing a wash liquid stream having a second, reduced concentration of amines. The wash stream with reduced concentration of amines is recycled back to the wash section to remove amines more effectively from the acid gas being scrubbed. The adsorbent material can be regenerated for reuse. Amine recovered from the regenerated adsorbent material can be recycled to the process for reuse.

1 . A method for reducing the concentration of amines in a wash liquid stream exiting a wash section in an acid gas scrubbing process, the method comprising:
 introducing the wash liquid stream exiting the wash section of the acid gas scrubbing process to an adsorbent material, wherein the wash liquid stream has a first concentration of amines, and   flowing the wash liquid stream having the first concentration of amines through the adsorbent material, the adsorbent material retaining at least a portion of the amines thereby providing a wash liquid stream having a second, reduced concentration of amines.   
     
     
         2 . The method of  claim 1 , wherein the wash liquid is water or an organic solvent. 
     
     
         3 . (canceled) 
     
     
         4 . The method of  claim 1 , wherein the acid gas being scrubbed is CO 2 . 
     
     
         5 . The method of  claim 1 , wherein the adsorbent material is activated carbon. 
     
     
         6 . (canceled) 
     
     
         7 . The method of  claim 1 , wherein amines comprise hydrophobic amines. 
     
     
         8 . The method of  claim 1 , wherein the adsorbent material is in the form of a fixed adsorbent bed to which the wash stream having the first concentration of amines is introduced. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 1 , wherein the adsorbent material has an average adsorption efficiency, which is at least 30% for a run time of 1 hour to 15 hours. 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 1 , wherein the adsorbent material has a working capacity, which is about 0.015 g-amine/g-adsorbent to about 0.5 g-amine/g-adsorbent. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . A method for reducing the concentration of amines in an acid gas scrubbing process gas effluent, the method comprising
 introducing exhaust gas containing acid gas into an absorber vessel, the vessel containing a solvent comprising a solution having less than 50% water and one or more amines;   flowing the exhaust gas through the solvent whereby at least a portion of the acid gas from the exhaust gas is absorbed by the solvent and at least a portion of the solvent is absorbed by the exhaust gas thereby forming a gas having an increased concentration of amine and a reduced concentration of acid gas;   washing the gas with the increased concentration of amine with a wash liquid in a wash section thereby removing at least a portion of the amine from the gas and absorbing the removed amine into the wash liquid;   introducing the wash stream exiting the wash section to an adsorbent material, wherein the wash stream has a first concentration of amines,   flowing the wash stream having the first concentration of amines through the adsorbent material, the adsorbent material retaining at least a portion of the amines thereby providing a wash stream having a second, reduced concentration of amines, and   recycling the wash stream having the second, reduced concentration of amines to the wash section in order to be reused therein, whereby providing a recycled wash stream with a relatively low concentration of amines to the wash section improves effectiveness of amine removal in the wash section thereby reducing the concentration of amines in the acid gas scrubbing process gas effluent.   
     
     
         26 . The method of  claim 25 , wherein the wash liquid is water or organic solvent. 
     
     
         27 . (canceled) 
     
     
         28 . The method of  claim 25 , wherein the acid gas being scrubbed is CO 2 . 
     
     
         29 . The method of  claim 25 , wherein the adsorbent material is activated carbon. 
     
     
         30 . The method of  claim 25 , wherein amines comprise hydrophobic amines. 
     
     
         31 . A method of regenerating an adsorbent material for reuse, the method comprising
 introducing steam or organic solvent to the adsorbent material, which has an initial concentration of amines adhered thereto, and   treating the adsorbent material by flowing the steam or organic solvent there through whereby at least a portion of the adhered amine detaches from the adsorbent material such that the adsorbent material has a second, reduced concentration of amines adhered thereto after treatment with steam or organic solvent thereby enabling reuse of the adsorbent material.   
     
     
         32 . The method of  claim 31 , wherein the adsorbent is treated with steam or organic solvent. 
     
     
         33 . (canceled) 
     
     
         34 . The method of  claim 31 , wherein the amine comprises hydrophobic amines. 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . The method of  claim 31 , wherein the adsorbent material is activated carbon. 
     
     
         38 . (canceled) 
     
     
         39 . The method of  claim 31 , wherein the amine is detached at a rate of from 0.005 g amine/g-carbon-minute to 0.025 g amine/g-carbon-minute. 
     
     
         40 . The method of  claim 31 , wherein the adsorbent material is regenerated in a time period between 5 minutes and 30 minutes. 
     
     
         41 . The method of  claim 31 , wherein the steam temperature is from 100-150° C. 
     
     
         42 . (canceled) 
     
     
         43 . (canceled) 
     
     
         44 . (canceled) 
     
     
         45 . (canceled) 
     
     
         46 . (canceled) 
     
     
         47 . (canceled) 
     
     
         48 . (canceled) 
     
     
         49 . The method of  claim 31 , wherein the amine is derived from a hydrophobic solvent comprising N-methylbenzylamine and a mixture of di-ethyleneglycoldibutylether, tri-ethyleneglycoldibutylether, and tetraethyleneglycoldibutylether. 
     
     
         50 . The method of  claim 50 , wherein the amine is derived from a hydrophobic solvent consisting of N-methylbenzylamine and a mixture of di-ethyleneglycoldibutylether, tri-ethyleneglycoldibutylether, and tetraethyleneglycoldibutylether.